1. Field of the Invention
The present invention relates to a storage medium having stored therein a stereoscopic image display program for stereoscopically displaying an image produced by using an augmented reality technique, a stereoscopic image display device, a stereoscopic image display system, and a stereoscopic image display method.
2. Description of the Background Art
There are conventional augmented reality techniques for synthesizing and displaying an image (virtual image) of a virtual space with an image (image captured by a camera) of a real space. There are also techniques for stereoscopically displaying images using a plurality of images captured by a plurality of cameras.
For example, Japanese Laid-Open Patent Publication No. 2008-146109 describes a device for stereoscopically displaying an image produced by using an augmented reality technique. That is, this device captures an image of the vicinity of a marker placed in a real space with a camera, and calculates the positional relationship between the camera and the marker by using the captured image. Then, an image (virtual image) of an object in a virtual space is produced by using this positional relationship, and the image is synthesized with the captured image. Thus, it is possible to display an image obtained by synthesizing a virtual object with a captured image of the real space. The device described above displays two images captured by two, left and right, cameras respectively on the left and right screens of a head-mounted display, thereby making it possible to stereoscopically show an image to the user. Therefore, with the device described in Japanese Laid-Open Patent Publication No. 2008-146109, it is possible to stereoscopically display an image obtained by synthesizing a captured image and a virtual image with each other.
However, Japanese Laid-Open Patent Publication No. 2008-146109 assumes that the size of the marker is known, and fails to consider problems occurring when the size of the marker is unknown or when there are markers of a plurality of sizes in a case where an image produced by using an augmented reality technique is stereoscopically displayed.